基于VOF模型的泵试验台汽蚀筒流场的CFD研究

CFD Research on Flow in Cavitation-tank of Pump Test-bed Based on VOF Model

泵试验台汽蚀筒内的流动是具有自由表面的复杂流动。以叶片角为-2°,型号为JM-211的混流泵为例,在其设计工况点Q=2 200 m3/h下,运用VOF模型,对江苏大学流体中心多功能试验台汽蚀筒的流动进行了内部流场数值计算,并与试验值进行了对比分析。数值计算得到了汽蚀筒内部的速度矢量图、两层稳流栅(整流器)附近横截面的压力分布图,以及出口速度、压力分布图。分析结果表明,两层稳流栅后流速稳定,压力分布较为均匀;泵进口压力试验值与计算所得汽蚀筒出口压力值非常接近。因此,该汽蚀筒进出口和稳流栅达到了试验所要求得泵进口压力且压力稳定。同时,研究结果表明VOF模型是模拟水泵试验台汽蚀筒内流动的一种有效方法。

Because of free surface, the flow in cavitation-tank of pump test-bed is complex. As regard to the JM-211 mix-flow pump with -2° Made angle, the cavitation-tank of multi-functional test-bed of Engineering Research Center for Fluid Machinery of Jiangsu University is simulated under the design condition Q= 2 200 m^3/h by using VOF models. The distributions of velocity and pressure in the cavitation-tank, the rectifiers and the exit are analyzed. And the calculation results are compared with those from experiments. The analytical results indicate that the distribution of velocity and pressure after the rectifiers are well-proportioned. The pressures of the pump inlet and outlet of the cavitation-tank are close. The design of inlet and rectifiers of the cavitation-tank can achieve the steady pressure required at the pump inlet. And the results also indicate that the VOF models are available for the simulation of flows in water-tank of pump test-bed.